Anyway, I mentioned something a week or so ago in 20splinters about doing stuff that a female body's not supposed to be able to do, but my headmates insisted that I not write it out fully from a public internet place like the library I was at. no such issue here!
Stuff like this happens generally only when I'm half asleep, I guess because I'm too aware of the body's gender when I'm awake, and there's just certain stuff like manners that while I ignore quite a few, sorry, but rubbing up against some one when you're horny, especially if they might still be asleep, is just something that I think men should be shot for. But I have been known to do it a time or few when I'm half-asleep.
So the body's still sort of in a relationship with a bisexual male body, and a couple months ago he crawled into bed with me when I was asleep. I sort of woke up, curled up against his back, and started having erotic dreams. He kind of half-woke me, said he could feel me about to penetrate his ass and told me to go ahead. So I went ahead and fucked him up the ass, got both of us off. This body, being female, is not supposed to be capable of that., but we both felt it.
I make no claims of understanding science or magic or knowing proper procedure for proving anything. I just go with my gut instincts mainly, or what feels good when the moments right for that. Take that and make whatever you want of it.